Boiler furnace



July 1, 1930. c. CHAPPUIS BOILER FURNACE Filed June 1, 1926 2 Sheets-Sheet l July 1, 1930. c, c ms 1,769,286

BOILER FURNACE Filed June 1, 1926 2 Shieet s-Sheet 2 Patented July 1, 1930 unite-a I stares 1.76a2sc CHARLES GHAPPUIS, OF LAU SANNE, SWITZERLAND BOILER rummon Application filed June 1, 1926, Serial No. 112,896, and in France June 8, 1925.

i said furnace is of the complete combustion type, in which only apart of the air supply is delivered through the grate, the other part being delivered above the fuel layer, at the point at which the combustible gases are dis engaged, and also through the loading column, should such be used.

My said apparatus is characterized by the fact that I dispose in series upon the path of the gas, two chambers either in succession or superposed whereof one serves to form the mixture of the gases issuing from the layer of fuel with the air admitted above the latter, and the other serves as a combustion chamber for the said mixture.

In the known types of large-sized boilers for locomotivesand for like industrial purposes, which are horizontally disposed in order to increase the grate surface, the grate as well as the refractory lining of the furnace are subject to a rapid deterioration inasmuch as thecomplete combustion of the gas takes place in the layer of fuel and directly above the latter. In this manner the fuel is raised to a very high temperature, so thatthe ash or slag will be melted, resulting in a very rapidwear of the furnace walls and the grate. Furthermore, by this formation of slag, the grate is almost entirely obstructed; This formation of slag is particularly observed when coal having fusible ash is employed.

Another disadvantage in the use of the said furnaces, when utilized with industrial boilers, consists in the fact that the heat can only be transmitted by convection, so that the output will be less .thanthat obtained in the cases in which the heat is transmitted partly by convection and partly by radiation.

In' my said invention I obviate these two disadvantages by the use of two chambers which are placed in series-or are superposed.

The first of the said chambers is so disposed that there will be produced therein only a very imperfect mixture of the additional air admitted above-the layer of fuel, with the combustible gases. The second chamber is vided with bafile devices tending to setup a whirling motion whereby the components will be entirely mingled.

The. first-mentioned chamber, into which there is admitted the additional air and without any intimate mixture with the gas currents, serves as apreparatory chamber for the combustion, whilst the second chamber operates as a chamber for complete combustion. This second chamber comprises a roof and walls which are good conductors of heat, so that the excess of heat produced by the combustion of the gas, relatively tov the limiting temperature, which is that of the decompositionv of the carbonic acid, will be transmitted to the boiler by radiation. H I

In this manner I am enabled to increase. theoutput of the boiler to an appreciable degree, since the combustion chamber may perate at a theoretical temperature whichfexceeds the temperature of decomposition of carbonic acid and water vapour, without the losses of heatto which such decomposition is usually subjected, this improvement being due firstly to the use of a radiating roof, and

secondly to the fact that the admission of the additional air may be regulated.

The appended drawing shows by way of example two constructional forms of a furnace according to my'invention, adapted respectively to a stationary boiler with movable grate and to a locomotive boiler with movable grate.

Fig. 1 is a section of the first apparatus, on the line I I of Fig. 2.

Fig. 2 is a section on the line II-II of v Fig. 1.

' Fig. 3 is a section, analogous to Fig. 1, of the second apparatus.

Figs't and 5 are sections'made respectively on the lines IV-IV and V-V of Fig. 3.

Referring to thefirst form of construction (Figs. 1 and 2) it is observed that aportion of the additional air is supplied at the top of the loading column 1, after a preliminary heating by a jacket 8, so as to draw all the products of distillation which are formed in the said column, through the layer of incandescent fuel 10, disposed on the movable grate 6. The other part of the additional air is supplied to the furnace, above the fuel, through the aperture 9, after a preliminary heating by the acket 7.

The portion of the furnace serving for the combustion of the products of the distillation and of the gasifying is divided into two superposed chambers 3 and 4:. Into the lower chamber 3 are delivered the products due to the distillation, combustion and gasifying of the fuel on the grate, and also the additional air which is preliminarily heated and is supplied through the aperture 9. The said chamber is so arranged that there will be produced only a very imperfect mixture of the gaseous combustible products with the pre liminarily heated air, this being effected by leaving but a small space above the said aperture. The upper chamber l is on the contraryso disposed as to effect this mixture in an int-imate manner, thus affording the complete combustion of the gases before they are delivered to the boiler, this being obtained by employing a chamber'of sufficient size and providing it with baflies. At the top of the chamber l is th roof 19 which is a very good conductor of heat and issuitably corrugated to increase its radiating surface.

In the second form of construction (Figs.-

3 to 5), the fuel is loaded directly upon the grate. which is extended to the left of the furnace itself for a certain distance.

The air makes contact with the fuel only a short distance before the plane of the section IVIV, so that there will be no ignition of the fuel at the rear part of the grate.

This air, which may pass through a double partition provided upon the front face of the boiler in order to obviate heat losses to the exterior, enters in part into the lateral air jackets 7, and for another part below the grate 6, passing through the grate into the fuel and drawing with it the distillation products. The part of the air passing through the jackets 7 traverses the same in the horizontal direction and finally attains the chamber 3 into which are also delivered the combustible products from the distillation, gasifying and combustion.

The complete combustion of the said prod ucts takes place in the chamber a, in the same conditions as in the preceding apparatus.

What I claim is:

1. In a boiler furnace having a continuously moving grate and a loading column disposed above said grate for supplying fuel thereto; the combination of a preparatory chamber for the combustion associated with said grate, a complete combustion chamber adapted to receive the gases from said first mentioned chamber, and having a roof and walls which are good conductors of heat, means for circulating air through said grate into said first mentioned chamber, other means for circulating air through the unburned fuel contained in the loading chamber into said first mentioned chamber, means for supplying additional air above said grate, means for preliminarily heating said additional air, and baffles and ribs provided in the roof and walls of said complete combustion chamber for producing a more complete combustion.

2. In a boiler furnace having a continuously moving grate, the combination of a preparatory chamber for the combustion associated with said grate, a complete combustion chamber adapted to receive the gases from said first mentioned chamber and having a roof and walls which are good conductors of heat, means for circulating air through said grate into said first mentioned chamber, means for supplying additional air above said grate, means for preliminarily heating said additional air, and bafiies and ribs provided in the roof and walls of said complete combustion chamber for producing a more complete combustion. V

8. In a boiler furnace having a continuously moving grate and a loading column disposed above said grate for supplying fuel thereto, the combination of a preparatory chamber for the combustion associated with said grate, a complete combustion chamber adapted to receive the gases from said first mentioned chamber, and having a roof and walls which are good conductors of heat, means for circulating air through said grate into said first mentioned chamber, other means for circulating air through the unburned fuel contained in the loading chamber into said first mentioned chamber, means for supplying additional air above said grate, and means for preliminarily heating said additional air. V

4. 'In a boiler furnace having a continuously moving grate and a loading column disposed above said grate for supplying fuel thereto; the combination of a preparatory chamber for the combustion associated with sald grate, a complete combustion chamber adapted to receive the gases from said first mentioned chamber and having a roof and walls which are good conductors of heat, means for circulating air through said grate into said first mentioned. chamber, other means for circulating air through the unburned fuel contained in the loading chamber into said first mentioned chamber, a lateral aperture in' said first chamber above said grate, and a jacket around said first mentioned chamber and connected with said chamber through said aperture.

5. In a boiler furnace having a continuously moving grate and a loading column disposed above said grate for supplying fuel thereto; the combination of a preparatory chamber for the combustion associated with said grate, a complete combustion chamber adapted to receive the gases from said first mentioned chamber, and having a roof and walls which are good conductors of heat, means for circulating air through said grate into said first mentioned chamber, other means for circulating air through the unburned fuel contained in the loading chamber into said first mentioned chamber above I said grate, and a jacket around said first mentioned chamber and connected with said chamber through an aperture, and baffles and ribs provided in the roof and walls of said complete combustion chamber for producing a more complete combustion.

6. In a boiler furnace having a continuously moving grate; the combination of a preparatory chamber for the combustion associated with said grate, a complete combustion chamber adapted to receive the gases from said first mentioned chamber and having a roof and walls which are good conductors of heat, means for circulating air through said grate into said first mentioned chamber above said grate and a acket around said first mentioned chamber and connected with said chamber through an aperture, and baflies and ribs provided in the roof and walls of said complete combustion chamber for producing a more complete combustion.

In testimony that I claim the foregoing as my invention, 1 have signed my name hereto.

CHARLES CHAPPUIS. 

